Detection of measles vaccine in the throat of a vaccinated childFever occurring subsequent to measles vaccination is related to the replication of the live attenuated vaccine virus. In the case presented here, the vaccine virus was isolated in the throat, showing that subcutaneous injection of an attenuated measles strain can result in respiratory excretion of this virus.

Outbreak of Measles Among Persons With Prior Evidence of Immunity, New York City, 2011This is the first report of measles transmission from a twice vaccinated individual. The clinical presentation and laboratory data of the index were typical of measles in a naïve individual….Of 88 contacts, four secondary cases were confirmed that had either two doses of measles-containing vaccine or a past positive measles IgG antibody. All cases had laboratory confirmation of measles infection….This outbreak underscores the need for thorough epidemiologic and laboratory investigation of suspected measles cases regardless of vaccination status.

Vaccine Failure

Changing Pertussis Epidemiology: Everything Old is New AgainPertussis was made notifiable in the United States in 1922. For 2 decades, reported cases were never under 100 000 and in 1934 peaked at over 265 000….whole-cell vaccines were replaced by acellular vaccines, first as the fourth and fifth doses beginning in 1992 and then for the entire childhood series beginning in 1997. Since that time, 2 important and unprecedented changes have occurred in the epidemiology of pertussis: the emergence of disease among vaccinated adolescents during the early 2000s and more recently the emergence of disease among school-aged children….The epidemics in 2010 and 2012 had a dramatically different epidemiology. Of the 27 550 cases reported in 2010, over 9000 occurred in in California….The highest incidence was observed in infants under 1 year of age, but an unusually large burden of disease occurred among children aged 7–10 years. The large majority of the children in this age group with pertussis were fully vaccinated with 5 doses of diphtheria and tetanus toxoid, acellular pertussis (DTaP), indicating a problem of vaccine failure rather than failure to vaccinate….Case counts [for the whole US] in 2012 reached 48 277—more than were reported in any year since 1959….Collectively, these observations led to the hypothesis that the epidemics were being driven largely by waning of immunity and redevelopment of susceptibility within the birth cohorts of children vaccinated with acellular vaccines, even in the face of recent booster doses.

Resurgence of Whooping Cough May Owe to Vaccine’s Inability to Prevent Infections The article, published in F1000 Research, points to the differences in mucosal immunity between whole-cell pertussis (wP) vaccines and the newer acellular pertussis (aP) vaccines, first introduced in the 1990s, as playing a pivotal role in the resurgence of the disease. “This disease is back because we didn’t really understand how our immune defenses against whooping cough worked, and did not understand how the vaccines needed to work to prevent it,” said Christopher J. Gill, associate professor of global health and lead author of the article. “Instead we layered assumptions upon assumptions, and now find ourselves in the uncomfortable position of admitting that we may made some crucial errors. This is definitely not where we thought we’d be in 2017.”

The future of measles in highly immunized populations. A modeling approachA computer model was created to study the effect of the measles elimination program in the United States on the number of susceptibles in the population. The simulation reveals that in the prevaccine era, approximately 10.6% of the population was susceptible to measles, most of whom were children less than 10 years of age. With the institution of the measles immunization program, the proportion of susceptibles in the population fell to 3.1% from 1978 through 1981, but then began to rise by approximately 0.1% per year to reach about 10.9% in the year 2050. The susceptibles at this time were distributed evenly throughout all age groups….The results of this study suggest that measles elimination in the United States has been achieved by an effective immunization program aimed at young susceptibles combined with a highly, naturally immunized adult population. However, despite short-term success in eliminating the disease, long-range projections demonstrate that the proportion of susceptibles in the year 2050 may be greater than in the prevaccine era. Present vaccine technology and public health policy must be altered to deal with this eventuality.

Pertussis Infections in Fully Vaccinated Children in Day-Care, IsraelVaccinated adolescents and adults may serve as reservoirs for silent infection and become potential transmitters to unprotected infants. The whole-cell vaccine for pertussis is protective only against clinical disease, not against infection. Therefore, even young, recently vaccinated children may serve as reservoirs and potential transmitters of infection.

Vaccine-Acquired Rotavirus in Infants with Severe Combined ImmunodeficiencyIn summary, vaccine-acquired rotavirus disease was detected after the administration of RV5 in three infants with SCID. In two of the three, rotavirus disease developed after receipt of the second rotavirus immunization, not the first, which may reflect early protection in infancy by transplacentally acquired maternal antibodies. Rotavirus clearance was accomplished only after successful immune reconstitution. These cases of rotavirus infection raise concerns regarding the safety of rotavirus vaccines in severely immunocompromised patients and the need to prevent vaccine-acquired disease, as with other live viral vaccines.

Vaccine-associated “wild-type” measlesWe report a 1-year-old boy who, 10 days after vaccination, developed vaccine measles which was clinically indistinguishable from the natural disease. Vaccine virus was detected by polymerase chain reaction in the patient’s nasopharyngeal secretions.

What is the cause of a rash after measles-mumps-rubella vaccination?We describe a 17-month-old child with fever and rash after measles-mumps-rubella vaccination. Detection of vaccine-strain measles virus in his urine by polymerase chain reaction confirmed the diagnosis of a vaccine reaction rather than wild-type measles. We propose that measles virus should be sought and identified as vaccine or wild-type virus when the relationship between vaccination and measles-like illness is uncertain.